The mountains are waking up and a significant avalanche cycle is expected this weekend as temperatures peak into the 20's.
Weather Forecast
Friday will see cloudy mild conditions with alpine winds dropping to light. The freezing level may rise to 2500m on friday. On Saturday,
Snowpack Summary
The 40cm of snow that fell last week in the Icefields area has been blown into windslabs below easterly alpine ridgelines. Mild conditions are warming this new snow and it is becoming wet and is sliding on the buried crusts. Relatively warm overnight temperatures are limiting the development of a supportive crust.
Avalanche Summary
Several loose wet avalanches were reported along the Icefields Parkway on all aspects and well into the alpine. These avalanches have been involving last week's storm snow and have been running far (300 to 400 m) with little mass. Most are size 1 to 1.5 but a few are up to size 2.
Confidence
Timing or intensity of solar radiation is uncertain on Friday
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.